On 7 March 2014 14:47, Larry Linder <larry.lin...@micro-controls.com> wrote:

> I am looking for a way to check the functionality of an Ethernet port on a
> 4
> mo old new system.   We use this box for number crunching and reducing
> data.
> Since no one uses the desktop we left it as "Gnome" and set up network.
>  This
> also the same box we found the SL 6.x had a broken driver for the chip set.
> Thanks to some serious help we were able to download the driver for the
> Ethernet chip set and it worked for a long time.
> After a power failure on a clear day we noticed that it would boot and run
> but
> no intranet.   The power failure was city wide for about 5 sec.  Just
> enough
> to turn on the UPS,s and EM Lights.
> I have look on the net and there is a lot of people offering suggestions
> but
> nothing you can hang you hat on.  Most just reference a lot of
> applications.
> Tried:
> drop down's for "preferences" and network set up.  restart "network" &
> NetworkManagement" .  These look OK.
> Apps:
> "ifconfig"
> etho:  says that it read a large number of packets and transmitted none.
> "ss"
> gives a lot of information but Its pretty criptic to say the least.
> The Ethernet chip set is on the mother board and I hate to dismantel it
> replace the mother board and have the same problem.  I was looking for a
> way
> to test it with a loop back scheme and monitor the transmission with a
> scope.

The cost of doing that is going to be more than a board and warranty if it
is 4 months old. Mainly because if it can recieve but not send then there
are 3 possible problems:

1) The ethernet card is fried. You can pay for a $10.00 replacement card
before you figure out what a correct signal looks like.
2) The wire is fried.
3) The port on the switch is fried.

The usual way to check things is the following:
1) If the box is really reading stuff you can do a tcpdump and see what
packets are being seen on the network.
2) Move the wire from the box to a different port on the switch. This will
see if the problem is with the switch.
3) Replace the wire.
4) If you have a grant get an ethernet probe device for a couple thousand
dollars (I think). They can test all of the above and tell you where the
line might be fried if it is buried in cables etc.

The oscillascope items might show you that you are getting a signal, but it
won't tell you if that wave is in any form or shape what the computer can
understand. To do that you will need to either duplicate a working signal
over a similar distance of cable (to deal with what degredation might be
there) or have some sort of litmus available (which is usually the probe

> The Ethernet chip set supports 10/100/1000 megHz.   Because of the size of
> the
> data sets we need the 1 g. rate.   We plan to upgrade our entire network
> to 1
> G router, and switches once this problem is resolved.
> Only change one thing at a time.
> Larry Linder

Stephen J Smoogen.

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